Non-orthogonal multiple access (NOMA) has been attracting attention as a radio access technology (RAT) for a fifth generation (5G) mobile communication system following Long Term Evolution (LTE)/LTE-Advanced (LTE-A). In non-orthogonal multiple access, signals of users interfere with each other, but a signal for each user is taken out by a high-precision decoding process at the reception side. Non-orthogonal multiple access, in theory, achieves higher cell communication capability than orthogonal multiple access.
As examples of non-orthogonal multiple access, for example, there are multiple access schemes using interleave division multiple access (IDMA) and superposition coding (SPC). In such non-orthogonal multiple access, the same radio resources are allocated to a plurality of terminal devices.
Patent Literatures 1 and 2, for example, disclose technologies for allocating radio resources.